Mobile and stationary machines may include a power source for generating power. The power source may be any type of suitable energy generating device such as, for example, an engine or a generator. The mobile and stationary machines may also include powered devices that may use power generated or otherwise supplied by the power source. Such powered devices may include, for example, elements of a drive train for propelling the machine, one or more implements (e.g. an excavating tool), and parasitic devices (e.g. an air conditioning compressor, an axle oil cooler pump, etc.). At times, power requests from the powered devices may conflict because the power source may not be capable of fulfilling each and every power request.
If power requested by the powered devices exceeds the available power from the power source, some or all of the powered devices may not receive sufficient power, and/or the power source may stall or fail. Power source failures may result in machine downtime and decreased efficiency. Intelligently distributing power to different parts of the machine may help to reduce power source failures. In addition, intelligently distributing power from the power source to the powered devices may involve deciding which powered devices will receive power and how much power they will receive.
Existing power distribution systems do not consider the parasitic devices when determining the distribution of power from the power source. Such parasitic devices may be necessary for the adequate function and control of the drive train elements and implements and may draw power from the power source when the drive train elements and implements are operating. Because the existing power distribution systems do not consider the parasitic devices when determining the power distribution, the power actually consumed by the powered devices may still exceed the available power from the power source.
One attempt to consider parasitic devices when intelligently distributing power from the power source can be found in U.S. Pat. No. 6,842,689 (the '689 patent) issued to Andres et al. on Jan. 11, 2005. The '689 patent discloses a power system that supplies power to a plurality of power consuming devices. The power system includes an engine, a main power recipient (i.e., a transmission) and a plurality of parasitic devices. The system determines a gross power value which is equivalent to the total power demanded by the main power recipient and the parasitic devices. If the gross power exceeds current demand, the speed of the engine may be increased, thereby producing more power.
While the distribution system of the '689 patent may consider the parasitic devices when determining how to distribute power from the engine, the benefits of such distribution might be limited. In particular, by increasing the engine speed to resolve the power deficit, the engine may be operated at speeds that may be sub-optimal. In addition, if the engine is already generating the maximum power possible, increasing the engine speed may not be able to adequately power all of the powered devices.
The disclosed system is directed to overcoming one or more of the problems set forth above.